someone writes:
This book is probably similar to some of your other books listed that deal with Darwinism. It contains explanations based on Charles Darwin's own life. Included are evolutionary explanations of sex, romance & love, social cement, social strife, and morals. The section on evolutionary ethics is most interesting. I
especially liked his explanation of Satan and evil.

p. 368 "The concept of 'evil,' . . . doesn't fit easily into a
modern scientific world view. Still, people seem to find it useful, and
the reason is that it is metaphorically apt. There is indeed a force
devoted to enticing us into various pleasures that are (or once were) in
our genetic interests but do not bring long-term happiness to us and may
bring great suffering to others. You could call that force the ghost of
natural selection. More concretely, you could call it our genes (some
of our genes, at least). If it will help to actually use the word evil,
there's no reason not to."

and

p. 369 "In all these assaults on the senses there is a great wisdom --
not only about the addictiveness of pleasures but about their
ephemerality. The essense of addiction, after all, is that pleasure
tends to dissipate and leave the mind agitated, hungry for more. The
idea that just one more dollar, one more dalliance, one more rung on the
ladder will leave us feeling sated reflects a misunderstanding about
human nature -- a misunderstanding, moreover, that is built into human
nature; we are designed to feel that the next great goal will bring
bliss, and the bliss is designed to evaporate shortly after we get
there. Natural selection has a malicious sense of humor; it leads us
along with a series of promises and then keeps saying 'Just kidding.' .
. . Remarkably, we go our whole lives without ever really catching on."